JPH09327262A - Production of high-quality green tea immediately after preparation before screening - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing green tea which is just manufactured and not screened yet, capable of improving qualities of green tea, by removing components of an offensive small contained in green tea, coarse tea, Gabaron tea, etc., and contaminants such as dust. SOLUTION: Green tea material which is just manufactured and not screened yet is immersed in treating water for tens seconds and washed. Components of an offensive smell and other factorial components to reduce the qualities of green tea contained in the green tea material are eluted in the treating water or oozed and contaminants admixed in the green tea material or attached to it are washed away.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing rough tea which is a material for tea such as green tea, bancha, gavalon tea and the like.

[0002]

2. Description of the Related Art Tea such as green tea is subjected to steam heat treatment on raw tea leaves picked from a tea garden, and then subjected to heating such as rough kneading treatment, middle kneading treatment, and fine kneading treatment, kneading, and water reduction treatment. It is dried by heating to adjust the water content to a suitable level to obtain rough tea. And store this rough tea for an appropriate period,
After storage, the product (finished tea) is obtained by adding heat treatment, heating, sieving, and further combining.
It has been common for tea to be boiled and drunk for a long time, but in recent years it has been recognized that the dietary habits have diversified and that tea leaves themselves have health benefits. As a result, tea leaves have been used as fine powder for drinking along with the decoction, and powdered powder has been added to foods and foods for eating.

[0003]

[Problems to be Solved by the Invention] Tea has a unique aroma, umami, astringency, etc., which enhances its value as a favorite beverage.
This is a factor that reduces the quality of tea because it suppresses aroma and umami and causes discomfort. This "offensive odor" is potentially contained in fresh tea leaves, and it is revealed when rough tea is made. Its type and content affect the geology and soil quality of the area where tea plants are grown, as well as the climate and type of fertilizer. To be done. In addition, when rough tea is stored for a long period of time, a new offensive odor is generated due to the deterioration of the nitrogen component. Of course, this "unpleasant odor" had been recognized for a long time, but, as mentioned above, the usage of tea was constant before that.
Since the amount of consumption was low, tea trees were cultivated in a specific area where "offensive odor" was rarely generated, so no problem occurred. However, in recent years, tea leaves have also become drinkable and edible, and in particular, it has become more common to drink or eat it at room temperature or lower, with a low aroma and taste. "Unpleasant odor" has come to be recognized more strongly. In addition, this increased the consumption of tea, which forced us to cultivate tea trees even in areas that were different from the conventional ones, resulting in the production of tea with a strong "offensive odor". . Therefore, it has been desired to develop a method for reducing the content of the "offensive odor" component contained in tea and enhancing its quality. Further, as described above, tea such as green tea is obtained by subjecting the raw tea leaves picked from the tea garden to steaming heat treatment, and further heating and rubbing treatment, so that the product tea leaves adhere to the raw tea leaves. It is inevitable that contaminants such as dust and insect feces will enter. Particularly, in recent years, since tea has been consumed or eaten, these problems are becoming serious. As a measure to solve such a problem, conventionally, a method of washing fresh tea leaves before subjecting them to steam heat treatment has been tried. However, fresh tea leaves are much bulkier than crude tea, so in order to wash them, the washing device must be significantly larger than the steam heat treatment device or rough kneading treatment device. is there. Moreover, the washed raw tea leaves will deteriorate if they are not dehydrated and immediately subjected to steam heat treatment, and the quality of the product will be significantly deteriorated. Therefore, there is a restriction that the washing device must be installed in all tea manufacturing plants and connected to each steaming heat treatment device. Therefore, the washing of fresh tea leaves was rarely done except for removing the volcanic ash in the area where the volcanic ash fell on the tea garden and adhered to the tea leaves. By the way, contaminants adhering to raw tea leaves and entering rough tea can be removed by processing the raw tea leaves and then washing the rough tea leaves. Since the volume is remarkably small, a small cleaning device is sufficient. Moreover, if the method of washing rough tea is eliminated, it is not necessary to connect the washing device to the tea making device, and this can be installed in a desired place different from the tea making device to store the rough tea for a desired period. After storing it,
It is possible to perform washing treatment by desired amount, and it is also possible to remove dirt mixed in rough tea at the stage of processing raw tea leaves to rough tea or at the stage of storing or storing rough tea. There is also. However, from the past, if you touch rough tea slightly with water, it will become damp and lose the quality as rough tea, let alone soak it in water,
It was thought that the tea would become so-called "dried tea," so in the end, the technical idea of washing crude tea did not occur at all. The present invention aims to provide a method for improving the quality of tea by removing the "offensive odor" component contained in green tea, bancha, gabalon tea, etc., and also removing contaminants such as dust. There is.

[0004]

For the purpose of solving the above-mentioned problems, the present inventor has researched a method for obtaining a high-quality tea by removing the "off-flavor" of the tea. As a result, when the rough tea produced by a normal method such as green tea is immersed in water, the "offensive odor" component contained in the tea is eluted or exuded into the water and removed from the rough tea. It was found that the aroma and umami components in tea leaves hardly exude into water if the time is within about several tens of seconds, and the method of the present invention is provided based on this finding.

Raw tea leaves picked from a tea plantation are put into a tea leaf steamer to be subjected to steaming heat treatment, and then roughening treatment, middle kneading treatment, and refining treatment to make rough tea. Next, this raw tea is used as raw material tea, and this is immersed in treated water for several tens of seconds. Then, most or most of the "offensive odor" component and other components that deteriorate the quality of tea contained in the raw green tea are eluted or exuded into the treated water and then filtered from the treated water. Separate and heat dry immediately to obtain a product (rough tea). When the raw material tea is soaked in water, it can be stirred or subjected to ultrasonic vibration to promote the elution or exudation of the “offensive odor” component or the like. In addition, by adopting this method, the cleaning effect is exerted on the rough tea, and the pollutants attached to the raw tea leaves and adhering to or mixed with the raw tea, and the storage and storage of the raw tea The contaminants newly mixed in or attached to the inside are washed out and removed together with the "unpleasant odor" component and the like. "Unpleasant odor" components are relatively easily eluted or exuded into the treated water even when the temperature of the treated water is low, but effective components such as aroma components, umami components, and vitamin C have a low temperature. Therefore, it becomes difficult to elute gradually. Therefore, it is desirable that the treated water has a low temperature, and the treated water has a temperature of about 20 ° C. or less, preferably about 5 ° C. Further, it is desirable that the immersion time be shortened as the temperature of the treated water rises. For example, when the water temperature is about 20 ° C., it is preferably about 30 seconds or less. Ordinary rough tea that has been subjected to hot air drying, firing treatment, or the like, or one that has been once processed to the stage of finishing tea can be processed as the material rough tea. It is possible to use a net conveyor to filter the crude tea that has been soaked, connect it to a hot air dryer, and put the filtered material into the hot air dryer to continuously dry it. .

[0006]

[Function] When the raw tea is immersed in water for a certain period of time and then filtered, the "offensive odor" component contained in the raw tea is eluted or exuded into the water and is filtered from the raw tea. Then, by heating and drying this rough tea immediately, the "bad smell" component and the like are removed from the crude tea to give it a high quality.
When the raw tea is soaked in water, by stirring it or applying ultrasonic vibration, elution or exudation of "unpleasant odor" components, etc. is promoted, and a cleaning effect for rough tea is also provided. The pollutants that are mixed into the raw tea or are adhering to the raw tea are washed out from the raw tea, and these are also removed. Will be the one. When this finished tea is used to make finished tea (green tea, powdered tea, matcha), the finished tea is of high quality that does not contain "unpleasant odor" components or pollutants.

[0007]

EXAMPLES The method for producing high-quality rough tea according to the present invention will be specifically described below by taking the method of continuously cleaning the raw tea material as an example. In this embodiment, the rough tea cleaning device is composed of a gutter type washing machine 1, a net conveyor 2, a centrifugal dehydrator 3, a fluidized bed dryer 4 and a multi-stage hot air dryer 5. The tea is quantitatively charged into the gutter-type washing machine 1, the tea is dipped in the treated water to wash it, and then the rough tea is dropped together with the treated water on the net conveyor 2 and filtered, and the excess is removed by the centrifugal dehydrator 3. After removing the water droplets and further removing the residual water by the fluidized bed dryer 4, the multi-stage hot air dryer 5
The method to obtain the product rough tea by heating and drying is adopted. The gutter-type washing machine 1 has a gutter-shaped washing tank 11 having a charging chute 12 attached to the tip side and an outlet 13 formed at the terminal side, and quantitatively discharges a predetermined amount of material rough tea from the charging chute 12. It is formed so that treated water (washing water) is injected from an appropriate place at the same time as pouring, and the washed rough tea and treated water are discharged from the discharge port 13. A weir wheel 14 is installed in front of the discharge port 13, which constitutes the apparent rear wall of the washing tank 11 and the discharge port, and the rough tea and the treated water put into the washing tank 11 are thereby provided. The water is accumulated in the tank 11 and is discharged quantitatively so as to regulate the flow velocity of the treated water in the tank 11, in other words, the residence time of the material rough tea.
Further, the washing tank 11 is equipped with a feed wheel 15 at an appropriate position, and this is rotated at a peripheral speed substantially the same as the flow velocity of the treated water in the tank 11 so that all the rough tea is sequentially transferred toward the discharge port 13. In addition to that, a large number of fumes nozzles 16 are provided at the bottom of the washing tank 11, and the treated water is agitated by ejecting air from this to elute or exude the “unpleasant odor” component etc. from the raw tea. To enhance the cleaning effect on rough tea. The net conveyor 2 is provided between the outlet 13 of the washing tank 11 of the gutter type washing machine 1 and the centrifugal dehydrator 3, and the conveyor belt 21 is formed by using a filter material having a high drainage effect. Receiving treated water and rough tea discharged from the outlet 13,
The treated water containing the “unpleasant odor” components and contaminants that have been eluted or exuded from the material rough tea is filtered off, and the crude tea from which these have been removed is sent to the centrifugal dehydrator 3. The centrifugal dehydrator 3 is a drum type dehydrator, in which the drum 31 whose upper and lower surfaces are opened is formed of a filter cloth on its side peripheral surface, and its rotation shaft 32 is inclined by about 40 to 50 degrees. However, the rough tea supplied from the net conveyor 2 is dropped into an appropriate place on the inner surface of the side peripheral surface of the drum 31 and is introduced.
Further, in this dehydrator, the drum 31 is configured to alternately switch to two types of rotation speeds of a dehydration speed (high speed) and a rough brown lower feed speed (low speed), and the dehydration speed is set to 10 to 10 seconds. By rotating, the moisture adhering to the rough tea is removed, and then the dehydrated crude tea is transferred while switching to the lower feed speed of the crude tea, rolling downwards and dropping from the bottom surface and discharged. At the same time, new rough tea (with water attached) is charged to the drum 31 and the dehydration speed is switched again. The fluidized bed dryer 4 is an ordinary continuous dryer, and the multi-stage hot air dryer 5 is a tea making dryer using high-humidity hot air (for example, Japanese Patent Application No. 8-106397). The tray 51 is provided with several stages of tray conveyors 52, and further, a brewing hopper 53 for rough tea is formed on the upper surface of the heating chamber 51, which is dried to a predetermined degree by the fluid dryer 4. When tea is introduced into the heating chamber 51 from here, rough tea is first placed on the uppermost tray conveyor.
Then, as the tray conveyor rotates, the tray conveyor is sequentially transferred to the lower tray conveyor while being heated by the high-humidity hot air sent from the high-humidity hot air generator 54, and finally subjected to a predetermined heat treatment so as to be taken out from the discharge port 55. Has become.

When washing rough tea, first, the gutter type washing machine 1
The weir wheel 14 is rotated while injecting the treated water into the washing tank 11 of, and the flow velocity of the treated water in the tank 11 is, for example,
When the temperature is about 20 ° C., the raw tea is adjusted so that it stays in the tank 11 for about 20 to 30 seconds. Then, the feed wheel 15 is rotated, and air is ejected from the fumes nozzle 16 to bring the treated water into an agitated state, while the material rough tea is quantitatively put into the washing tank 11. Then, the material rough tea is mixed with the treated water, and the "offensive odor" component and the like contained therein are eluted or leached into the treated water. At the same time, the pollutants attached to or mixed with the rough tea or the treated water enter the treated water. After a predetermined time has passed, clean rough tea is discharged together with the treated water from the discharge port 13, and the net conveyor 2
Pour on top. Then, the rough tea is filtered by the conveyor 2 and sent to the centrifugal dehydrator 3 in a state in which the "offensive odor" component and the like are removed. Then, the crude tea that has been moistened by removing the residual water by the centrifugal dehydrator 3 is sent to the fluidized bed dryer 4, the moist air is removed, and dried to the same level as the rough tea that has undergone the tea-making process. It is sent to the multi-stage hot air dryer 5 and hot humid air is applied to it for further drying, and the aroma is enhanced to obtain a product.

[0009]

As described above in detail, according to the present invention, by immersing the crude tea produced by the usual method such as green tea in water,
The "offensive odor" component contained in this crude tea is eluted or exuded into water to be removed, and the crude tea becomes of high quality. Moreover, at that time, if this is agitated or ultrasonically vibrated, elution and exudation of "unpleasant odor" components, etc. are promoted, and the cleaning effect is exerted on the rough tea, and the material The pollutants mixed in or adhering to it are washed from the crude tea, so that the crude tea becomes higher in quality and cleaner. And the product green tea etc. finished using this rough tea,
It is of extremely high quality, clean and free of "offensive odor". Also, by immersing rough tea in water, the finished product green tea etc. tends to have aroma and umami as compared to ordinary ones, making it excellent as cold tea and tea for tea bags. It is also suitable as edible tea. The method of the present invention has the same effect on ordinary rough tea that has been subjected to a treatment such as burning, or to a finish tea that has been subjected to a processing treatment. It is also possible to regenerate those that have an offensive odor or have a reduced aroma or taste.

[Brief description of drawings]

FIG. 1 is a system diagram showing an example of a rough tea cleaning device to which the present invention is applied.

FIG. 2 is a cross-sectional view showing a main part of a gutter type washing machine.

FIG. 3 is a sectional view showing a main part of a centrifugal dehydrator.

FIG. 4 is a cross-sectional view showing a main part of a multi-stage hot air dryer.

[Explanation of symbols]

 1 Gutter type washing machine 2 Net conveyor 3 Centrifugal dewatering machine 4 Fluidized bed dryer 5 Multi-stage hot air dryer 11 Washing tank 12 Input chute 13 Discharge port 14 Weir wheel 15 Feeder 16 Fume nozzle 21 Conveyor belt 31 Drum 32 Rotating shaft 51 Heating chamber 52 Tray conveyor 52 Heating chamber 53 Input hopper 54 High humidity hot air generator 55 Ejection port

Claims (4)

[Claims] 1. A raw tea prepared by subjecting raw tea leaves picked from a tea garden to steam-heat treatment and other tea-making treatments is used as a raw tea. A method for producing high-quality rough tea, which comprises filtering crude tea from the treated water when the factor that deteriorates the quality elutes or exudes in the treated water and heat-drying. 2. When the raw material tea is soaked in water, it is stirred or ultrasonically vibrated to give it a cleaning effect, thereby elution or exudation of "offensive odor" components and the like. The method for producing high-quality rough tea according to claim 1, wherein the pollutants adhering to or mixed with the raw tea are washed away. 3. The material rough tea is crude tea produced from raw tea leaves by a conventional method, and the rough tea is processed into a finishing tea or an intermediate step thereof. The method for producing the high-quality rough tea according to claim 1 or 2. 4. The treated water is cold water at 20 ° C. or less, preferably about 5 ° C., wherein the treated water is cold water.
To produce high quality rough tea of.